Method of hydrocarbon conversion



Patented June 1943 UNITED STATES PATENT, OFFICE- 2,321,604 METHODOFHYDROCABBON CONVERSION Vladimir A. Kalichevsky and George F. Hornaday,

woodblll'y, N. J.

, assignors to Socony-Vacunm Oil Company, Incorporated, New York, N. Y.,a corporation of New York No Drawing. Application December 22, 1939.

Serial N0. 310,568

2 Claims. (Cl. 196-52) United States patents of Eugene Houdry andassociates.

In short the method of cracking is one in which a petroleum oil, heatedto about 850 F. in the vapor form, is passed at that temperature througha space containing a contact mass composed of particles,'pellets, orgranules consisting of alumina and silica, having the nature of ahydrated aluminum silicate. The vapors, in passage through said mass areconverted to a large extent to material of gasoline boiling range, ofdesirable high octane value, a portion of the materlal remainingunchanged and of properties essentially the same as the charge. Theremainder of the charge is converted into gaseous hydrocarbons and intoa small amount of cokey material which remains upon the contact mass andis periodically burned on by a regeneration which may be in situ.

The material which is used as a catalyst ap pears to be possessed of a.physical capability of promoting reaction instead of a chemicalcapability and this ability is distributed in vary degrees through widevariety of materials, natural, partially processed, and synthetic, whichin general are of the clay typ comprising in their composition alumina,silica, or both, such as.

Iullers earth, Filtrol clays, bauxite, silica gel, naturally occurringadsorbent clays generally related to fullerg earth, acid washedadsorbent clays and other partially processed clays, and many syntheticaluminates, silicates, and mixtures thereof,

The material which passes through the reaction zone apparently withoutsubstantial change is known as recycle stock. This invention hasspecifically to do with a modification of the operation which producesunexpected and marked changes in this recycle stock.

As pointed out previously, the normal recycle stock is a gas oil, notunlike the original charge in physical properties. For example inanoperation conducted at 875 F. and 30# per square inch gauge Pressure, toproduce about 32% of gasoline of 400 F. end point and about 58% ofrecycle stock from a charging stock which in turn was a recycle stockderived from one similar treatment of gas oil from Oklahoma City crude.the propertieg of the charge and of the recycle stock produced therefromwere as follows:

Table I Recycle W stock 224 0.03 0.02 41.3 Lou t This invention is basedupon the discovery that unexpected and useful results flow from theintroductlon of small amounts of ammonia into the stream of vaporsentering the catalyst mass. Without substantial change in the yields ofeither gasoline or cycle stock, and without substantial change in thecharacter of the gasoline produced, useful changes in the character ofthe cycle stock are observed. The physical characteristics of thenormally produced cycle stock fit it quite well for use as a fuel incompression ignition engines, but, probably due to its having beenpassed through a cracking process, its chemical nature is so altered asto give it a lower cetane numbed, that is, to make it a less desirablefuel for compression ignition engines than was the gas oil from which ithas been derived. Upon the introduction of ammonia into the crackingstep it has been observed that the cycle stock produced has anunexpected improvement in cetane number, in amounts of commercialsignificance, sufllcient to considerably enhance the usefulness of theproduct .8s a fuel for compression ignition engines, and that withoutmaterial change in the other properties of the product.

To show the eilect of this change: which 1;. 0L

duced recycle stock with the previously mentioned normally producedrecycle stock.

Table II Catalytically Catalytically cracked in cracked in Propertiesabsence presence of ammonia ammonia 30.8 30.6 10 10 214 186 0.18 0.24137 141 0.09 0.07 Frags The above results were experienced whenintroducing to the Japors undergoing cracking from 0.2-0.7 percent byweight of anhydrous ammonia. Usually not more than one percent by weightof charge is sufficient to accomplish tial cracking during vaporization,superheating said vapors to a temperature appropriate for catalyticcracking to gasolinewithout substantlal 'cracking of said vapors duringsaid heating, adding a small amount of ammonia to said vapors, thenpassing said vapors into contact with a clay-like catalytic contact massto accomplish a substantial cracking of the high boiling hydrocarbons togasoline, and fractlonating the ammonia is brought. about.

2. That method for the conversion 0! petroleum hydrocarbons comprisingvaporizing hydrocarbons of high boiling point without substantialcracking during vaporization, superheating said vapors to a temperatureappropriate for catalytic cracking to gasoline withoutsubstantial lcracking of said vapors during said heating, a d-- ing a small amount'oiammonia, not more tham.

passing said vapors. into contact. with a ,claylike catalytic contactmass to accomplish a sub-:

the desired results. It will be observed that the physical properties orthe product have not been changed, but that there has been an increaseof 6 points in cetane number.

stantial cracking of the high boiling hydrocarbons to gasoline, andfractionating. the prod-- nets of cracking to separate therefrom theeaseline and a heavier oil of light gas oil nature, whereby, withoutsubstantial change in the physical properties or yields of gasoline andgas oil produced, an increase in cetane number 0! the gas oil over thatproduced in the absence of said ammonia is brought about.

' VLADIMIR A. KALICKEVSKY.

GEORGE F. HORNADAY.

the case in the Patent Office.

CERTIFICATE OF CORRECTION. Patent No. 2,521,60h. June 15,1915.

VLADIMIR A. KALICHEVSKY, ET AL.

It is hereby certiiied that error appears in the printed speoificationof the above numbered -patent requiring correction as follows: Page 1,first coluinn, line 55, for T'vary" read varying--; and second column,line 16, for "S. U. vie. m 100 F." read --S. U. visc. 100 F.-'; line14.2; for "numbed" read --number--; and that the said Letters Patentshould be read with this correction therein that the Same may conform tothe record of Signed and sealed this lOthday'of August, AND. 1914.5.

Henry Van Arsdele, (S ea1) I 7 Acting Commis sioner of Patents.

